Terminal apparatus, base station apparatus, and method

Abstract

A terminal apparatus includes: a reception unit configured to receive an RRC reconfiguration message including a DRB configuration and a processing unit, wherein the processing unit establishes an SDAP entity based on conditions that a DRB identity included in the DRB configuration is not part of a configuration of the terminal apparatus, an SDAP configuration is included in the DRB configuration, and an SDAP entity corresponding to a PDU session information element included in the SDAP configuration does not exist, and indicates establishment of a user-plane resource for a PDU session to an upper layer based on an additional condition that the SDAP entity corresponding to the PDU session information element does not exist before the RRC reconfiguration message is received.

The invention claimed is: 
     
       1. A terminal apparatus for communicating with a base station apparatus, the terminal apparatus comprising:
 reception circuitry configured to receive a Radio Resource Control (RRC) reconfiguration message including a Data Radio Bearer (DRB) configuration from the base station apparatus; and 
 processing circuitry, wherein 
 the processing circuitry, in processing the received RRC reconfiguration message, is configured to 
 determine a) that a DRB identity included in the DRB configuration is not part of a current configuration of the terminal apparatus, determine b) the a Service Data Adaptation Protocol (SDAP) configuration is included in the DRB configuration, and determine c) that an SDAP entity corresponding to a Protocol Data Unit (PDU) session indicated by a PDU session information element included in the SDAP configuration does not exist, 
 in a case that the processing circuitry determines a) that a DRB identity included in the DRB configuration is not part of the current configuration of the terminal apparatus, b) that the SDAP configuration is included in the DRB configuration, and c) that the SDAP entity corresponding to the PDU session indicated by the PDU session information element included in the SDAP configuration does not exist, 
 establish an SDAP entity and 
 further determine d) whether it is before receiving the RRC reconfiguration message or not that the SDAP entity corresponding to the PDU session indicated by the PDU session information element does not exist, 
 in a case that the processing circuitry determines that the SDAP entity corresponding to the PDU session indicated by the PDU session information element does not exist, 
 indicate establishment of a user-plane resource for the PDU session information element to an upper layer. 
 
     
     
       2. A communication method used by a terminal apparatus for communicating with a base station apparatus, the communication method comprising the steps of:
 receiving a Radio Resource Control (RRC) reconfiguration message including a Data Radio Bearer (DRB) configuration from the base station apparatus; 
 in processing the received RRC reconfiguration message, determining a) that a DRB identity included in the DRB configuration is not part of a current configuration of the terminal apparatus, determining b) that a Service Data Adaptation Protocol (SDAP) configuration is included in the DRB configuration, and determining c) that an SDAP entity corresponding to a Protocol Data Unit (PDU) session indicated by a PDU session information element included in the SDAP configuration does not exist; 
 in a case of determining a) that a DRB identity included in the DRB configuration is not part of a current configuration of the terminal apparatus, b) that the SDAP configuration is included in the DRB configuration, and c) that the SDAP entity corresponding to the PDU session indicated by the PDU session information element included in the SDAP configuration does not exist, 
 establishing an SDAP entity and 
 further determining d) whether it is before receiving the RRC reconfiguration message or not that the SDAP entity corresponding to the PDU session indicated by the PDU session information element does not exist, 
 in a case determining that the SDAP entity corresponding to the PDU session indicated by the PDU session information element does not exist, 
 indicating establishment of a user-plane resource for the PDU session information element to an upper layer.